Cummins ISL CM850 (2003-06) Fault Code: 1687 PID: SPN: 3050 FMI: 0 Catalyst Over Temperature – Data Valid but Above Normal Operational Range – Most Severe Level. Very high temperatures have been detected in the aftertreatment system.

Cummins ISL CM850 (2003-06) Fault Code: 1687 PID: SPN: 3050 FMI: 0 Catalyst Over Temperature – Data Valid but Above Normal Operational Range – Most Severe Level. Very high temperatures have been detected in the aftertreatment system.

This fault is triggered when the temperature at the catalyst exhaust outlet exceeds the maximum allowable temperature for a given engine rating.

On-Board Diagnostic (OBD) Information:

1)The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2)The ECM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. The MIL lamp and fault code can also be cleared with INSITE? electronic service tool.
3)The fault code will be cleared from the memory after 40 consecutive drive cycles when the diagnostic runs and passes.

Possible epairs:

1)